Although Angulo stayed on his feet throughout the beating, Weeks decided he had seen enough 47 seconds into the 10th round and waved off the bout after Alvarez clocked his opponent with an uppercut.

“He stopped the fight because he knew what was going on,” Alvarez said through a translator while still in the ring. “I was doing my job. I was so secure in my jab. Of course I was a little tired, but I could have gone 10 more rounds.”

The sold-out crowd at the arena wasn’t convinced. They booed ferociously and threw trash Alvarez’s way to protest the stoppage.

It didn’t help that Angulo spent several minutes pleading his case for why the fight should have gone on after the loss.

“I’m frustrated,” Angulo said. “They should have let it go to the end. The referee was wrong this time.”

Any rational observer, however, could understand Weeks’ viewpoint. Welts dotted Angulo’s face after he displayed practically no defense against the faster and stronger Alvarez through nine rounds. Angulo had one strong push during the eighth round when he got Alvarez on the ropes, but other than that, he had only won a single round on any of the three judges' scorecards.

Ringside doctors checked on Angulo multiple times in between rounds, and Weeks himself looked close to stopping the beatdown before the 10th round. He even appeared to warn Angulo of his intentions in the corner before the 10th.

But Angulo couldn’t do anything different as he opened the frame taking more punishment from Alvarez in the form of combinations led by jabs and body shots.

“I was in Angulo’s territory and was able to go toe-to-toe with him,” Alvarez said. “Tonight, I was the better fighter. He got hurt severely. I definitely rebounded from the Mayweather fight.”

Alvarez improved to 43-1, bouncing back from the only loss in his career last September to Mayweather while Angulo fell to 18-4.

Check back to lasvegassun.com later for full coverage of the fight and scroll below for our live blog.

Pre-main card

It might sound melodramatic to call a 23-year-old’s fight a turning point in his career.

It might be also be accurate when it comes to Saul “Canelo” Alvarez tonight. Long viewed as the future of boxing, Alvarez suffered his first setback in his last fight.

And there appears to be no reprieve despite it coming against the world’s best boxer in Floyd Mayweather Jr. People are now questioning whether Alvarez was worth the hullabaloo.

Alvarez (42-1) can silence those feelings, or amplify them, with tonight’s pay-per-view bout against Alfredo “El Perro” Angulo (18-3) at the MGM Grand Garden Arena. No one is going to confuse Angulo for Mayweather, but the fellow Mexican fighter is accomplished enough to test Alvarez in a different way.

Angulo performs like the pit bull he’s named after. He comes forward and attacks, with lesser regard for his own safety or defense than expected for a high-level fighter.

That should play right into the hands of Canelo, a prolific counter-puncher, if he’s as strong as everyone seemed to believe a year ago. If the flaws Mayweather helped accentuate extend to another bout, then Angulo could pull off the upset.

He’s currently around a plus-500 underdog in sports books, with Alvarez ingrained as a minus-700 favorite. It would be a damning blow to Alvarez’s future prospects if he lost in the first pay-per-view card Golden Boy Promotions has asked him to carry.

Alvarez clearly has some of the characteristics necessary to sell buys. He’s charismatic and entertaining. To downplay his role in helping Mayweather set the record for the top-grossing pay-per-view ever would be a mistake.

Alvarez has more than connected with the Hispanic market, which will make up the majority of the sold-out crowd tonight. That leaves open the possibility of those waving Mexican flags instead of wearing fighter-specific attire switching allegiances.

If Angulo pieces together some combinations and gets off to a fast start, it could be trouble for Alvarez. Angulo could steal some of his thunder.

It’s an important night for Alvarez.

Stay tuned to lasvegassun.com for live round-by-round coverage with scoring of Canelo vs. Angulo.

Demetrious "Mighty Mouse" Johnson slammed his hands down on his UFC flyweight championship belt. Somewhere else in Rogers Arena, Rory MacDonald surely looked on with envy. Johnson and MacDonald put on dominant performances in the UFC's first trip to Vancouver in three years. Johnson defended his title for the fourth time, not allowing Ali Bagautinov to win any of their five fast-paced rounds. That couldn't quite top MacDonald, who barely let Tyron Woodley touch him in an all-important welterweight co-main event. MacDonald hopes the performance leads him to an opportunity to claim space alongside Johnson in the UFC champion's club.